7 years ago
29 November, 2016
Research carried out by an international team led by Professor Jack Cuzick of the Queen Mary University of London had previously found that this breast cancer prevention drug reduced the risk of breast cancer in high-risk groups by 53%. (2).
Anastrozole reduces the action of the enzyme aromatase, which converts androgens (male sex hormones) to oestrogen. High levels of oestrogen are associated with an increased risk of breast cancer. Oestrogen encourages a high cell division rate, meaning there is less time for DNA repair and an increased risk for mutations that may lead to cancer. Oestrogen-positive breast cancers require high levels of oestrogen for their growth.
In post-menopausal women, aromatase is mainly found in fatty tissues (such as the breasts), muscle and skin, where most oestrogen is produced.
Anastrozole helps prevent breast cancer in post-menopausal women by blocking the action of aromatase, thereby blocking oestrogen production. It is a prevention treatment for breast cancer following hormone receptor-positive breast cancer diagnosis (3). It is also used as a prevention treatment for women at high risk of developing breast cancer – but this treatment is not currently available on the NHS.
A woman is at ‘high risk’ (4) of breast cancer if she:
The 2014 study by Cuzick et al. (2) indicated that Anastrozole has fewer and less serious side effects than tamoxifen, which is also used as a preventative treatment. However, a more recent study (5) suggests both drugs have a similar number of side effects, though the side effects are different. Women may also develop resistance to Anastrozole (6). Drug resistance means a drug will be less or no longer effective.
Breast Cancer UK supports preventative medicine and this breast cancer prevention drug, which can be used to help reduce breast cancer in high-risk groups. However, most breast cancers are not in women at high risk. Breast cancer will affect 1 in 8 women at some point in their lifetime (7), and many do not identify as high-risk.
Breast Cancer UK also believes that it is important to question and continue to research why apparently high-risk groups are at higher risk today than they were 50 years ago. A 2003 study (8) found that the risk of getting breast cancer by age 50 for a woman carrying a BRCA mutation who was born before 1940 was 24%, but for those born after 1940 was 67%. This suggests that our lifestyles and modern-day environments could increase our vulnerability to this disease. To truly prevent more breast cancers, we must continue to research and better understand all of the risk factors for breast cancer – including our exposure to potentially harmful chemicals in everyday products such as hormone disrupting chemicals.
The NICE draft guideline update is out for consultation until 29 December 2016.
15 February 2024
Breast Cancer UK (BCUK) is pleased to welcome our new Ambassador, Michelle Ogundehin. Michelle has been our fantastic supporter over the years, including blog writing and supporting various campaigns we...Read full story
16 June 2022
Breast Cancer UK joined hundreds of charities at a Service of Thanksgiving at Westminster Abbey to celebrate the remarkable difference they make in their communities. His Royal Highness, The...Read full story
13 June 2022
In May our Head of Science, Margaret Wexler, spoke at a parliamentary event on pesticides. Organised by The Pesticide Collaboration and RSPB, and hosted by Luke Pollard, MP for Plymouth,...Read full story